This invention relates to improved air-drying protective coatings. In a particular aspect, this invention relates to improved air-drying alkyd enamels containing a reactive diluent.
Because of environmental and occupational hygiene concerns --as well as economics --there has been considerable effort in recent years to develop protective coatings without the use of the organic solvents which have conventionally been used in paints, varnishes, enamels, etc. Water-borne coatings, for example, have been very successful, but they have limited storage stability due to hydrolysis and performance properties are strongly affected by humidity.
One effort in recent years has been directed to replacing, at least in part, the inert, volatile solvents commonly used in alkyd resin formulations with a reactive solvent (or diluent) which reacts with the alkyd during the drying process and becomes a part of the final coating. For example, Emmons et al. in U.S. Pat. No. 4,311,624, disclosed the use of methacryloxyalkyl and/or acryloxyalkyl esters of drying oils along with dicyclopentenyloxyalkyl acrylates and methacrylates. Emmons et al. also review earlier efforts in this field.
Although the efforts of previous workers have apparently been technically successful, the disclosed reactive diluents have proven to be rather expensive and have not enjoyed wide-spread use. Therefore, there is a need for reactive diluents which are economically attractive as well as being technically useful.
Accordingly, it is an object of this invention to provide improved air-drying protective coatings.
It is another object of this invention to provide air-drying alkyd enamels containing a reactive diluent.
It is still another object of this invention to provide reactive diluent esters for use with air-drying alkyd enamels.
Still another object of this invention is to provide articles which have been coated with the improved alkyd enamel.
Other objects of this invention will be apparent to those skilled in the art from the disclosure herein.